Abstract: An electrode for a fuel cell element including a hydrophobic graphite support layer; a semi-hydrophobic electro-catalyst layer including an electro-catalytically active material in a carbon substrate and a polytretrofluorethylene (PTFE) content having a first concentration; and a hydrophilic electro-catalyst layer including an electro-catalytically active material in a carbon substrate and having a PTFE content having a second concentration that is less than the first concentration.

Abstract: A fuel cell sensor is provided for detecting the presence of acetylene and hydrogen in a fluid. The sensor includes a sensing element having first and second gas diffusing electrodes spaced from one another. The first gas diffusing electrode can be used for sensing acetylene. The second gas diffusing electrode can be used for sensing hydrogen. A fuel cell spacer having an acidic electrolyte is disposed between the sensing element and a common electrode. The sensing element can be configured to have a specific ratio of the area between the first gas diffusing electrode in relation to the area of the second gas diffusing electrode.

Abstract: An electrode for a fuel cell element including a hydrophobic graphite support layer; a semi-hydrophobic electro-catalyst layer including an electro-catalytically active material in a carbon substrate and a polytretrofluorethylene (PTFE) content having a first concentration; and a hydrophilic electro-catalyst layer including an electro-catalytically active material in a carbon substrate and having a PTFE content having a second concentration that is less than the first concentration.

Abstract: A micro fuel cell sensor having laminated gas permeable membrane. The sensor comprises a housing, first and second gas diffusing electrodes spaced from one another, a fuel-cell spacer having an acidic electrolyte disposed between said first and second electrodes, and two gas permeable membranes. The first gas permeable membrane comprises a polymer laminated on a metal substrate, wherein the substrate comprises pores that have dimensions at least less than one-half the thickness of the polymer film.

Abstract: A fuel cell sensor is provided for detecting the presence of acetylene and hydrogen in a fluid. The sensor includes a sensing element having first and second gas diffusing electrodes spaced from one another. The first gas diffusing electrode can be used for sensing acetylene. The second gas diffusing electrode can be used for sensing hydrogen. A fuel cell spacer having an acidic electrolyte is disposed between the sensing element and a common electrode. The sensing element can be configured to have a specific ratio of the area between the first gas diffusing electrode in relation to the area of the second gas diffusing electrode.

Abstract: A sensor system for measuring a plurality of chemical species is disclosed. The sensor system includes a plurality of semiconductor device sensor elements, wherein each sensor element includes at least one wide band gap semiconductor layer and at least one catalytic layer configured to have an electrical property modifiable on exposure to an analyte including one or more chemical species; and an acquisition and analysis system configured to receive sensor signals from the plurality of sensor elements and to use multivariate analysis techniques to analyze the sensor signals to provide multivariate analyte measurement data.

Abstract: A multi-gas sensor device for the detection of dissolved hydrocarbon gases in oil-filled electrical equipment. The device comprising a semiconductor substrate, one or more catalytic metal gate-electrodes deposited on the surface of the semiconductor substrate operable for sensing various gases, and an ohmic contact deposited on the surface of the semiconductor substrate. The semiconductor substrate comprises one of GaN, SiC, AlN, InN, AlGaN, InGaN and AlInGaN. A method for sensing gas in an oil-filled reservoir of electrical equipment, comprising providing a sensor device, immersing the sensor device in the oil-filled reservoir, allowing the gases emitted from the oil to interact with the one or more catalytic metal gate-electrodes, altering the gas as it contacts the catalytic metal gate-electrodes and altering the sensitivity of the sensor.

Abstract: A multi-gas sensor device for the detection of dissolved hydrocarbon gases in oil-filled electrical equipment. The device comprising a semiconductor substrate, one or more catalytic metal gate-electrodes deposited on the surface of the semiconductor substrate operable for sensing various gases, and an ohmic contact deposited on the surface of the semiconductor substrate. The semiconductor substrate comprises one of GaN, SiC, AlN, lnN, AlGaN, InGaN and AlInGaN. A method for sensing gas in an oil-filled reservoir of electrical equipment, comprising providing a sensor device, immersing the sensor device in the oil-filled reservoir, allowing the gases emitted from the oil to interact with the one or more catalytic metal gate-electrodes, altering the gas as it contacts the catalytic metal gate-electrodes and altering the sensitivity of the sensor.

Abstract: A multi-gas sensor device for the detection of dissolved hydrocarbon gases in oil-filled electrical equipment. The device comprising a semiconductor substrate, one or more catalytic metal gate-electrodes deposited on the surface of the semiconductor substrate operable for sensing various gases, and an ohmic contact deposited on the surface of the semiconductor substrate. The semiconductor substrate comprises one of GaN, SiC, AlN, InN, AlGaN, InGaN and AlInGaN. A method for sensing gas in an oil-filled reservoir of electrical equipment, comprising providing a sensor device, immersing the sensor device in the oil-filled reservoir, allowing the gases emitted from the oil to interact with the one or more catalytic metal gate-electrodes, altering the gas as it contacts the catalytic metal gate-electrodes and altering the sensitivity of the sensor.

Abstract: A micro fuel cell sensor having laminated gas permeable membrane. The sensor comprises a housing, first and second gas diffusing electrodes spaced from one another, a fuel-cell spacer having an acidic electrolyte disposed between said first and second electrodes, and two gas permeable membranes. The first gas permeable membrane comprises a polymer laminated on a metal substrate, wherein the substrate comprises pores that have dimensions at least less than one-half the thickness of the polymer film.

Abstract: A multi-gas sensor device for the detection of dissolved hydrocarbon gases in oil-filled electrical equipment. The device comprising a semiconductor substrate, one or more catalytic metal gate-electrodes deposited on the surface of the semiconductor substrate operable for sensing various gases, and an ohmic contact deposited on the surface of the semiconductor substrate. The semiconductor substrate comprises one of GaN, SiC, AlN, InN, AlGaN, InGaN and AlInGaN. A method for sensing gas in an oil-filled reservoir of electrical equipment, comprising providing a sensor device, immersing the sensor device in the oil-filled reservoir, allowing the gases emitted from the oil to interact with the one or more catalytic metal gate-electrodes, altering the gas as it contacts the catalytic metal gate-electrodes and altering the sensitivity of the sensor.

Abstract: An apparatus for measuring partial hydrogen pressure in a gas stream is described. The apparatus includes a housing with micro-fuel cell sensor disposed therein. The sensor includes a sensing element having first and second gas diffusing electrodes spaced from one another with an acidic electrolyte disposed between the electrodes. A first gas permeable membrane separates the first electrode from an external gas stream. A second gas permeable membrane separates the second electrode from atmospheric air. Electrochemical charging of the first electrode occurs when hydrogen from a gas stream diffuses through the first membrane to react with the first electrode, while the potential of the second electrode remains unchanged. The potential difference between the first and second electrodes measured as current is identified to represent the sensor output.

Abstract: An apparatus and method are provided for continuously monitoring the operation of electrical equipment and preventing critical operational failures. The invention quantitatively determines the concentrations of gas and/or vapor (including water) components in an insulating fluid on a real time basis. An increase of one or more detected chemical components signifies an actual or potential electrical problem with the equipment. The preferred apparatus consists of a gas extractor, an infrared gas analysis instrument, and a gas diaphragm pump. Gas and water vapor components are extracted from the insulating fluid by permeating through a membrane in a gas extractor. The gas and/or vapor components are then brought into an infrared gas analyzer by the gas diaphragm pump. A quad detector in the analysis instrument identifies and determines the concentration of three specified gases and/or the vapor simultaneously.

Abstract: An apparatus for measuring hydrogen content and partial hydrogen pressure in gas streams and a method of modeling the sensor based on the characteristics of the sensor. The apparatus includes a housing with micro-fuel cell sensor disposed therein. The sensor includes a sensing element having first and second gas diffusing electrodes spaced from one another with an acidic electrolyte disposed between the electrodes. A first gas permeable membrane separates the first electrode from an external gas stream. A second gas permeable membrane separates the second electrode from atmospheric air. Electrochemical charging of the first electrode occurs when hydrogen from a gas stream diffuses through the first membrane to react with the first electrode, while the potential of the second electrode remains unchanged. The potential difference between the first and second electrodes measured as current is identified to represent the sensor output.

Abstract: An apparatus for measuring hydrogen content and partial hydrogen pressure in gas streams and a method of modeling the sensor based on the characteristics of the sensor. The apparatus includes a housing with micro-fuel cell sensor disposed therein. The sensor includes a sensing element having first and second gas diffusing electrodes spaced from one another with an acidic electrolyte disposed between the electrodes. A first gas permeable membrane separates the first electrode from an external gas stream. A second gas permeable membrane separates the second electrode from atmospheric air. Electrochemical charging of the first electrode occurs when hydrogen from a gas stream diffuses through the first membrane to react with the first electrode, while the potential of the second electrode remains unchanged. The potential difference between the first and second electrodes measured as current is identified to represent the sensor output.

Abstract: An apparatus for measuring partial hydrogen pressure in a gas stream is described. The apparatus includes a housing with micro-fuel cell sensor disposed therein. The sensor includes a sensing element having first and second gas diffusing electrodes spaced from one another with an acidic electrolyte disposed between the electrodes. A first gas permeable membrane separates the first electrode from an external gas stream. A second gas permeable membrane separates the second electrode from atmospheric air. Electrochemical charging of the first electrode occurs when hydrogen from a gas stream diffuses through the first membrane to react with the first electrode, while the potential of the second electrode remains unchanged. The potential difference between the first and second electrodes measured as current is identified to represent the sensor output.